The New York City Police Department spent about 1 million hours making low-level marijuana arrests in the last decade, according to a report released Tuesday, a particularly surprising finding since the police force has been steadily reducing its number of uniformed officers since 2002.

Police officers made 440,000 arrests for low-level pot crimes between 2002 and 2012, states the report, which was prepared by members of the Drug Policy Alliance and the Marijuana Arrest Research Project. On average, each marijuana possession arrest took about two-and-a-half hours, ultimately the “equivalent of having 31 police officers working eight hours a day, 365 days a year, for 11 years, making only marijuana arrests.”

Anthony V. Bouza, a former NYPD commander, told the report authors that New York City’s current focus on marijuana arrests is comparable to the “roundup of gays” in the 1950s and 1960s.

“The offenses represent exactly the same level of risk to the public. Making marijuana arrests a priority is a waste of police resources and does not reduce street violence. Illegal, trivial, meaningless arrests undermine confidence in the justice system and corrupt the enforcers,” Bouza said.

The research was commissioned at the request of the New York City Council and New York State Legislature. In response to, in part, the extensive number of low-level pot arrests in the city (and the fact that multiple analysis have concluded those arrested are typically black or brown), last month Mayor Michael Bloomberg announced those arrested for possessing under 15 grams of pot will no longer be arrested but will be issued a ticket instead.

Marijuana is currently classified as a Schedule I drug by the federal Drug Enforcement Administration. As a result, the report says getting arrested for possession is often an arduous experience. Those arrested for small-scale possession are sometimes detained for days, and typically the arrest appears on a permanent criminal record.

NYPD Commissioner Ray Kelly, in a hearing before the City Council Public Safety Committee last week, said police officers are no longer being directed to arrest people who display marijuana in public view at the request of an officer (such as the result of a “stop and frisk”).

New Yorkers are arrested for low-level pot crimes more than any other offense, according to data put out by the Division of Criminal Justice Services. Legislation that would have decriminalized the open possession of under 25 grams of cannabis was shot down by Senate Republicans last year.

The NYPD has been cutting its numbers since Bloomberg took office in 2002. That year, there were about 37,000 uniformed officers on patrol, reports. Next year, the force will drop to a 21-year low of 34,500.

New York City spent $75 million arresting and jailing people for pot possession in 2010 alone. Up to $1 billion of taxpayer money may have been used to lock up and prosecute those offenders between 1997 and 2010, according to the report.